1970 napco c-60 front axle brake adjustment axle info

[sweetk30]

anyone got a idea on this sucker ?

no windows like the rear for a spoon .

never played with this style before . done lots and lots of the window stick the spoon in and click up .

it looks like there is 2 nuts on the bottom with a weird bolt and the end is crimped flat to grab with a small adjustable wrench maybe . then on each side rear the top is a reg old hex bolt .

looks like this axle basicly : http://67-72chevytrucks.com/vboard/s...ighlight=napco

will get pics and post up best possible.

[sweetk30]

well I asked a few old timers around town and even they had no real idea since its so old and 4x4 napco that you just don't see much of .

so I tore in to it today .

here is the run down .

pic # 1 = bottom of backing plate back side 2 adjustment bolts with jamb nuts and lock washers .

pic #2 = adjuster / shoe lower retainer unit removed / cleaned / wire wheeled to get it to work and understand how to make it adjust .

pic #3 = all cleaned up and lubed with copper anti-seize .

the jamb nuts back off just a bit .

then the pinched flat head gets turned as its a off set cam bolt . it has a round washer riding on it that the shoe lower hole sets over and all acts like a crude bearing piviot point.

the 2 pinched head adjuster bolts each have a pin mark in them to indicate were the adjustment currently is at . close together/center = new shoe or no major wear . the farther they away to the opposite sides of each other = worn out shoes and replacement of parts needed.

by the looks of it its not a 360* rotation of adjustment just a 180* range of adjustment . so you can roll the adjustment bolt each way and get the same results.

[sweetk30]

now for the upper nut /spring looking thing .

there what I think is a return limit stopper for the shoes / upper adjustment . this keeps the wheel cylinders from dropping all the way back in and having to pump the pedal up to get brakes.

pic #1 = backside of backing plate up near the 10-2 positions .

pic #2 = the closeup of the inside of the unit on the backing plate . this is a around a 360* range of motion for adjustment . so you will have to play with this to figure out what way to go . ( will be easy for me with apart )

pic #3 = whole backing plate .

the inside off set cam pushes on the brake shoe metal part its self to hold the shoe up and against the drum face .

[sweetk30]

next I took the backing plate / spindle off and removed the axle shaft WOW is that a BIG shaft and HUGE c/v style joint.

will get pics up next few days .

replacing the inner axle tube seals . someone did them WAY back in the day and installed them wrong and got them cocked and bent up inside.

they were leaking gear oil in to the closed knuckle and then thinning it out and leaking past the wheel seal and also the closed knuckle wipers . this was getting nasty stuff all over in the front end.

I got good seal #'s just got to hit the seal/bearing store in the am .

also looks like I might be able to install 2 seals per side for 2x the protection . the inner housing bore looks deep and the seal section of the shaft is long .

[sweetk30]

14x2 drums up front with reg style 2 pistion wheel cylinder.

man is it NOT FUN finding parts for these old girls.

here is the pass side / short shaft with a stock gm dana 60 necked down early style inner next to it .

and the spines dia is only .10 inch bigger than the 35 spline 60 inner . but as we know the teeth count is were the strength is at .

[USSkoval]

This is good info here, thanks for posting it

I'd like to think that one day I can use this info. Doubtful, but a larger 4x4 rig is on the bucket list.

[sweetk30]

I have not found hardly any info at all on these axles . . .

so I figure why not just post it up .

my stuff is already starting to pop up in searches I posted around a week ago .

[sweetk30]

so I tracked down a few brands of oil that's the 00 spec stuff. for me its only 5gal per order and I don't need that much .

but with one place they had a cross reffrence list of what there oil converted from . . . one of them was a napa - sme 706612 and its a 32oz bottle worth for about 17bucks each . so for these big old knuckles I got 4 bottles . . . should do me up I think .

also I went to the seal shop today with size specs of the seal area on the shaft and housing bore . the seals I removed were replaced some time in the past and were just a smidge off . . .

we come up with a axle shaft seal for a 1957-1958-1959 chevy/gmc 1ton truck application . its a skf or Chicago rawhide 16650 part # .

the this was the closest seal we could find on the master book going by specs only . then I was able to find it on rockauto for $1.10 each close out price ( I got 4 ) and there listing specs and napa also gave the original use info .

man this has been a trip so far but hope its on its way to the end of the line.

[sweetk30]

closest thing I can find pic wise to the drum brakes on this old girl

no park brake parts like this picture.

[sweetk30]

got my skf / cr 16650 seals yesterday .

popped them in today . they fit NICE and snug . definitely had to use a seal driver and 4lb hammer to set them in good and easy with out walking all over the place .

tested them on the shaft also before install . they fit better / snug around the seal surface of the axle shaft over the wrong ones removed .

putting the axle back together today and hope to adjust the brakes up good with out to much trouble .

then when all done and think I am golden I will fill the knuckles with the GOO . . . and fyi I have had them next to the wood stove and the heat has made the 00 greese lube thin out a bit so it should be better to squeeze it in the fill holes over shelf temp thickness.

[sweetk30]

few pics

[sweetk30]

so I got it together today .

new inner axle seals / all guts back in / brakes on / and adjusted up good and snug .

still got the low pedal . first hit about on floor next hit directly after letting up is at the top and rock solid no drop .

got to figure out were the problem is before I give this back . . .

I found the trick for the 00 grease stuff. heat it on the wood stove up on some 2x2 tubing scraps. and the wood stove is hot air system so no major high heat direct on plastic tubes. . . do this to warm it way up then it squeezes threw the end nozzle in the upper hole on the ball of the ball/socket setup .

it seemed to start getting a little hard to fill after 1.75 bottles worth so that's were I stopped each side fill up . there 32o.z. each tube/bottle.

[sweetk30]

removed the front cover today to clean / reseal it . . . was ozzing oil near bottom .

WOW that diff is FULL hardly any room to fit a dime thickness between the ring gear and case body . cant even see the pinion gear . it even has a load bolt setup to control ring gear deflection . . . .old school stuff.

inside she looks just like a 14ff but MUCH BIGGER

7.20 gear ratio in there from way back then . open diff no traction device . and boy does she like gear oil almost 2 gal worth to fill up . the front napco axle

the t-case is a Rockwell t223 unit . 2.00 low range and it has a ramsey pto unit that's never been hooked up for use on the back of it . this old girl wanted 3 qrt of oil also with the drain / fill I did on it.

just about done with tinkering with this old girl and ready to go back to its home by mid week I hope . if I stop checking stuff over and finding more to fix . . .

with the 4 speed / 2.00 low / 7.20 gear / 39" tires she is 101.52 : 1 crawl ratio factory . . . no doubler required and if she was to ever get to 70mph ( tire and safety limits ) she would be 4350rpm

[sweetk30]

final post with info on the truck as it is now . post #233 http://67-72chevytrucks.com/vboard/s...320260&page=10